Brain, giant-cell glioblastoma

Giant cell glioblastoma is a rare morphologic variant of glioblastoma, a malignant primary brain tumour classified as WHO grade IV. Clinically, they are generally indistinguishable from conventional glioblastoma. Microscopically, the tumour is composed of giant cells, smaller fusiform cells, and variably, a reticulin network. The giant cells may have extremely bizarre and grotesque (“monstrocellular”) appearances, potentially measuring up to 500 microns in diameter; they may be lipidized; multinucleation is common. Atypical mitotic figures and geographic necrosis are also commonly observed, but unlike conventional glioblastoma, pseudopalisading necrosis and microvascular proliferation are rare features. Prognosis does not differ substantially from conventional glioblastoma.